Enable Remote Desktop Connections in Windows

Navigate to the System option in the control panel
Click on Remote Settings and enable remote connections to this PC.

6

Reboot your PC

You must reboot your workstation for the registry settings to take effect.

Test your connection and don't forget to add the port number after the IP Address. For example:

127.0.0.1:3388

Conclusion

This will allow you to have several workstations remotely accessible using different ports without the need for a VPN. You will also need to use the new port number internally if you need to remote into the workstation.

Keep in mind that this does leave the workstation open to attacks, so make sure you have a good password policy in place before you implement.

I agree with Goalieman but this quickly gets out of hand when you have to edit every PC and add the update to your NAT device to make it work. My preference is to RDP into one computer on the network and then launch a new RDP session to any of the others.

A vendor claims Ciscos hardware routers would out perform Sophos firewalls as gateway devices. Each vendor claims their stuff is superior. What do you think, is the hardware advantage enough to overcome the extra hop/processing cost?